Dynamic tensile failure of Laurentian granite subjected to triaxial confinement Available to Purchase

In this paper, a traditional split Hopkinson pressure bar system is modified to be able to conduct dynamic tests on rock specimens under triaxial stress conditions. Granite specimens are manufactured as Brazilian discs to examine the dynamic tensile failure of rocks, and to investigate the influence of the triaxial stress state and loading rate on the dynamic tensile strength of rocks. The experimental results reveal the rate-dependence phenomenon of the tensile strength. The effect of the triaxial stress state is divided into the influence of the hydrostatic stress and that of the pre-tension, and it is found that the dynamic tensile strength of rocks is almost independent on the pre-tension. An empirical equation is proposed to explain the dynamic tensile behaviour of rocks under triaxial stress state and it agrees well with the experimental results. This finding has a certain value for underground excavation that only the hydrostatic pressure needs to be considered to evaluate the dynamic tensile failure of rocks in the intermediate zone.